How to select the differential pressure value between V-cone flowmeter and orifice flowmeter

Manufacturers of throttling devices all know that when calculating the opening diameter of throttling devices such as orifice flowmeters and V-cone flowmeters based on field parameters, there is a problem involved, that is, how to select the maximum differential pressure value of the differential pressure transmitter? How to select the differential pressure value and how large should it be? It is related to many factors, such as: uncertainty, front and rear straight pipe sections, etc. Therefore, when calculating the opening diameter of orifice flowmeters and V-cone flowmeters, you must not blindly select a large differential pressure, but must comprehensively consider some relevant factors.

1. When the differential pressure value is large, the minimum straight pipe section required can be shorter. In view of this feature, for the orifice flowmeter, considering various economic factors, the opening value with the largest differential pressure should be selected; the V-cone flowmeter is relatively better. If the on-site fluid is a Newtonian fluid, the straight pipe section requirement of the V-cone flowmeter itself is relatively low. Even if it is shorter, it does not exist in comparison.

2. When the differential pressure is large, the β value becomes smaller, and the recommended minimum Reynolds number is smaller. In this case, the actual Reynolds number may be much larger than the recommended Reynolds number, so the flow coefficient tends to be stable and the measurement accuracy is improved.

3. For differential pressure transmitters, those with larger differential pressure are more stable than those with smaller differential pressure.

4. The above introductions are basically all advantages when the differential pressure is large. However, in many cases, when it develops to a certain extent, it will inevitably bring certain disadvantages. People who are familiar with the processing technology of orifice flowmeters and V-cone flowmeters should know that when the differential pressure is too large, the direct consequence is that the opening becomes very small, and the pressure loss is relatively large. The orifice flowmeter has a large pressure loss. If this is added, the cost caused by this pressure loss is considerable for the entire process system; V-cone flowmeters are slightly more moderate in comparison.

Therefore, in our daily production process, we cannot blindly recommend our users to choose a large differential pressure value. We must be truly responsible for our customers and for the company.